Pve..any roll is good..but I do personally use the ringing nail a lot...sounds awesome and looks awesome.

Up to you 🤷🏼‍♂️ I use a Kill Clip, Triple Tap Uriels Gift quite a bit and it gets the job done. Although I do wish for more Omolon Auto Rifles but make them into 600’s because I like those Autos the most, they feel the best to me. Also buff all Auto Rifles for PvE!

Everything is viable in pve.

600s don’t have enough damage to drop barrier shields consistently in the GM, you need 450s if you want to drop it easily and consistently. 450s are great and if you’re lucky and get a Dynamic away/elemental capacitor braytech your in the money. With a void sub class that thing is a sniper, bounce what so ever, it’s crazy.

They're okay. Especially if you get one with a good damage perk. But Bungie is deliberately keeping the 450s underpowered compared to other weapons because they returned Uriel's Gift to the game and don't want it dominating the Crucible meta like it did in vanilla D2. Right now 600 rpms are the best ARs in the game right...and will still probably be after the nerf they'll get in 10 days. Instead of trying to get a god-rolled Braytech, I'd get a good Gnawing Hunger. If you need one in the kinetic slot, I'm afraid that you'll have to go exotic with Monte Carlo. The only good legendary 600 rpm that isn't being sunset is the Iron Banner AR.